Electric bulb socket



Aug. 23, 1938. w. J. CLEMENTS ELECTRIC BULB SOCKET Filed May. 21, 1936.iffaweeys. l

M ,5. a p i6 7 5 M @W M Patented Aug. 23, 1938 PATENT OFFICE ELECTRICBULB SOCKET William J. Clements, Chicago, Ill., assignor to ClementsMfg. 00., Chicago, 111., a corporation of Illinois Application May 21,1936, Serial No. 80,938

1 Claim. (Cl. 113328) My invention relates to sockets for electric bulbsand is particularly adapted for employment in positions where the bulband socket are subjected to vibration. It may be employed, for example,as a lighting means for vacuum cleaners of the ,type in which a smalllight bulb is employed. Other purposes are, however, obvious, includingautomatic uses.

One of the purposes of my invention is the pro vision of a compact,strong, easily manufactured and eflicient socket, arranged to safeguardthe contacts.

Another object is the provision of such a socket in which the contactsare themselves employed for preventing unintended displacement of thebulb during use.

Other objects will appear from time to time in the course of thespecification and claim.

I illustrate my invention more or less diagrammatically in theaccompanying drawing in which:

Figure 1 is a plan view;

Figure 2 is a section on the line 22 of Figure 1, illustrating anelectric bulb in position;

Figure 3 is a bottom view;

Figure 4 is a section on the line 4-4 of Figure 1;

Figure 5 is a side elevation; and

Figure 6 is a section on the line 6-6 of Figure 5.

Like parts are indicated by like symbols J throughout the specificationand drawing.

Referring to the drawing, I generally indicates a base portion orsupport with which may be formed, preferably integrally, a generallycylindrical socket 2, the support having an open bottom 3 conforming tothe bore of the cylindrical socket but of slightly smaller diameter toprovide ledges 3a against which the lower edge of the bulb 4 abuts whenthe bulb is thrust a sufiicient distance into the socket portion. 2,serving thus as a limiting stop for the bulb to prevent excessivemovement inwardly and to prevent distortion of the contacts. The base Iand socket 2 are made of any suitable insulating material, such asbakelite, hard rubber, etc.

The base I is provided with a plurality of bottom channels 5 in whichmay be positioned spring contact fingers 6, each of said contactsterminating in a rounded outer end I, in the form of an upwardly convexpart. Associated with each such finger is a screw threaded conductivesleeve 8 of metal which may be set into the upper extensions 9 of thebase portion I. It will be understood that the entire socket structuremay be integrally formed of one piece of fiber or plastic material andthat the conductive members 8 are fitted or placed therein, either inthe course of formation of the socket or thereafter. They may beinternally screw threaded as at II] in order to receive the screws IIwhich serve to hold the fingers 6 in position and which also serve asexterior contacts. Nuts I2 may be positioned on the screws II or theymay be omitted and the screws I I may be so short that they do notoccupy the full interior of the screw threaded member 8, leaving spacefor a screw to be inserted from above to be attached to or to carry aconductor or for any other purpose. If the screw II extends beyond thebase as shown in Figures 1, 4, 5 and 6, a knurled nut I3 may be mountedon it to secure the conductors.

I illustrate oppositely positioned vertical grooves I5 on the inner faceof the cylindrical member 2, which grooves communicate at their lowerends with extensions I6 having upper notches II which, in connectionwith the projections I8 from the bulb 4 constitute bayonet locks. Itwill be understood that the spring contact fingers 6 normally thrustupwardly against opposed contacts I9 in the bottom of the bulb,providing actuating contacts for the bulb itself. The spring fingersperform the additional function of holding the projections I8 seated inthe notches I 1 whereby rotation of the bulb into releasing position canresult only if the operator presses downwardly on the bulb and thenpositively rotates it. Unintended rotation and release is madeimpossible and the bulb is firmly seated.

The base is apertured as at20 to receive any suitable securing screws 2Idiagrammatically illustrated in dotted lines in Figure 2, whereby thesocket as a whole may be positioned onthe vacuum cleaner or othermechanism or support with which it is used. 1

It will be realized that, whereas I have described and illustrated apractical and operative device, nevertheless many changes may be made inthe size, shape, number and disposition of parts without departing fromthe spirit of my invention. I therefore wish my description and drawingto be taken as in a broad sense illustrative or diagrammatic rather thanas limiting me to the precise showing of the drawing and description.

The use and operation of my invention are as follows:

When the socket is completed, the spring contact fingers 6 arepositioned within the grooves or depressions 5 and are secured thereinby screws II, which may be longer or shorter, or by some other means.The shape of the depressions 5 within the spring contact fingers 6 lieis such that they position and retain the fingers, preventing theirtwisting or swinging about their point of attachment, thus preventingtheir being bent away out of proper contact position. For some purposeslong screws M will be used as shown; for other purposes they will beshort and the contactwill be made by threaded members inserted from theoppositedirection.

With the contact fingers and suitable attachments in position, thesocket is placed wherever it is to be used, on a vacuum cleaner, in thehead lamp of an automobile, or any other stationary or moving piece ofapparatus Suitable contacts are made with necessary'conductors which insome manner or other engage the sleeves 8. The bulb is now inserted. Itis inserted in the hollow of the socket, the guiding pins t8 of the bulbbeing positioned within the grooves Hi. The bulb is normally positionedso that the inner end "of its base contacts the shoulders or ledges 30..These serve as a positive and unyielding stop and so prevent excessinward movement of the bulb. In devices of this general type, it hasbeen customary in the past to have contact fingers serve the addedpurpose of limiting stops for the inward movement of the bulb.andfrequently the bulb is pushed in too far and having no positive stop,distorts the contact spring fingers and renders them inaccurate oruseless, sometimes pushing them entirely and permanently out of the way.

It is the purpose to avoid this in the present construction by theprovision of the ledges which constitutea positive mechanical stop sothat the bulb is not only properly stopped or limited, but the springcontact fingers are positively protected against excess inward movementof the bulb and consequently excessbending of the springs.

When the bulb has been pushed into its limit, it is turned in thenecessary direction to bring the pins 18 into the depressions I 'L; Itis then released and the spring contact fingers .force it upward to seatthe pins 58 in the notches H. The turning movement of the bulb cannotdistort or displace the spring fingers because they are held againstturning movement by the walls of the grooves or channels 5 in which theylie.

The upward inclination, as shown in Figure 4, which, whatever theposition of the socket is an inclination in the direction of the lampbase, in-

creases the pressure of the springs against the trative and diagrammaticrather than as limit- 'in'g.

' Another advantage of this construction is in its ease of manufacture.The construction comprising the groove l5, extension I6, and notch I1having an open'bottom can be made by cutting or molding, simply, whereasthe conventional closedbottom bayonet lock groove cannot, and it is oneof the objects of the invention to provide a construction which may beeasily and cheaply manufactured.

I-claim:

A socket for electric light bulbs including a support provided with acentral aperture, a hollow cylindrical wall upstanding from the supportand surrounding the aperture therein and defining a lamp base receivingsocket, the inner surface of the socket and support aperture beingprovided with a continuous, longitudinal, open-ended groove adapted toreceive a lug on a lamp base, rib members on the support extendingradially of said socket, the under side of said support being recessedin line with said ribs, said recesses opening into the aperture of thesupport, a'resilient contact in each of said recesses, each of saidcontacts having a free end terminating within said support aperture, anupwardly facing annular shoulder within the socket intermediate the endsof said longitudinal groove and adapted to limit inward movement of alamp base placed in the socket, exposed terminal members penetrating therib members and securing the contact members within the recesses withtheir free extremities above said annular shoulder for engagement withcooperating contact members carried by a lamp base, and a downwardlyfacing stop shoulder within said longitudinal groove, positioned to beengaged by said lug on the lamp base to limit upward movement of thelamp under the influence of said spring contact members.

WILLIAM J. CLEMENTS.

